The bus would be the way to go, unless willing to spend the $$ on private car big enough to accommodate 4 people plus luggage.

I've done the train before (in reverse, coming from Suzhou), and the Sofitel is just a short cab ride from the Suzhou train station so could be an option, but would be tough if you had any real luggage. Hauling luggage up and down stairs at the train station can be brutal. Also would be somewhat inefficient as you would need to take a cab (or maybe 2) to the station, buy the tickets, and then wait for the train. By the time you get on the train, the bus could be halfway there.

Safe Travels